Absolute Properties of the Main-Sequence Eclipsing Binary Star WW Camelopardalis

Abstract

We present absolute photometric observations in uvbyβ and 5759 differential observations in the V filter (the most complete light curve ever obtained) measured by a robotic telescope, as well as radial velocities from spectroscopic observations of the detached, eccentric, 2.3 day, double-lined, eclipsing binary star WW Camelopardalis. Absolute dimensions of the components are determined with high precision (better than 1% in the masses and radii) for the purpose of testing various aspects of theoretical modeling. We obtain 1.920 ± 0.013 M⊙ and 1.911 ± 0.016 R⊙ for the primary, and 1.873 ± 0.018 M⊙ and 1.808 ± 0.014 R⊙ for the secondary. The effective temperatures and interstellar reddening of the stars are accurately determined from new uvbyβ photometry: 8350 ± 135 K for the primary and 8240 ± 135 K for the secondary, corresponding to a spectral type of A4m for both, and 0.294 mag for Eb-y. The metallic-lined character of the stars is revealed by high-resolution spectroscopy and uvbyβ photometry. Spectral line widths give rotational velocities that are synchronous with the orbital motion in a slightly eccentric orbit (e = 0.0098). The components of WW Cam are main-sequence stars with an age of about 490 Myr according to models.